Change the definition of the vertex buffer from an imported model

I want to change the vertex defit开发者_StackOverflow社区ion from a model. I have a definition called VertexPositionColorNormal. But the code errors on the draw statement that there isn't any color.

How do I solve this?

This is controlled by the Effect. My guess is that you have Effect.UseVertexColor True. Either set it false for models without vert color or change the artwork.